Venous Insufficiency Treatment Method

ABSTRACT

The method of treating varicose veins and other vascular diseases provides sclerosant fluid through a catheter into the body vessel to be treated. The catheter has a lumen and a plurality of sidewall exits. The sclerosant fluid is provided under sufficient pressure so that it comes out of each exit as a jet of fluid with sufficient velocity to impinge on the vessel wall substantially orthogonal to the wall and thus minimize dilution of the sclerosant fluid and optimize coverage. A movable sheath on the catheter permits selecting a portion of the exits to be uncovered and thus create an infusion zone for the jets of sclerosant fluid which approximately match a desired treatment zone.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of pending U.S. application Ser. No.11/303,818, filed Dec. 15, 2005, which claims priority to patentapplication Ser. No. 10/393,922, filed Mar. 20, 2003, which claimspriority to U.S. Provisional Application No. 60/370,050, filed Apr. 4,2002, all of which are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a method for treatment of vasculardiseases, and more particularly, to a method for treating varicose veinsusing catheter and sclerosing agent.

BACKGROUND OF THE INVENTION

Veins are thin-walled and contain one-way valves that control bloodflow. Normally, the valves open to allow blood to flow into the deeperveins and close to prevent back-flow into the superficial veins. Whenthe valves are malfunctioning or only partially functioning, however,they no longer prevent the back-flow of blood into the superficialveins. As a result, venous pressure builds at the site of the faultyvalves. Because the veins are thin walled and not able to withstand theincreased pressure, they become what are known as varicose veins whichare veins that are dilated, tortuous or engorged.

In particular, varicose veins of the lower extremities are one of themost common medical conditions of the adult population. It is estimatedthat varicose veins affect approximately 25% of adult females and 10% ofmales. Symptoms include discomfort, aching of the legs, itching,cosmetic deformities, and swelling. If left untreated, varicose veinsmay cause medical complications such as bleeding, phlebitis,ulcerations, thrombi and lipodermatosclerosis.

Traditional treatments for varicosities include both temporary andpermanent techniques. Temporary treatments involve use of compressionstockings and elevation of the diseased extremities. While providingtemporary relief of symptoms, these techniques do not correct theunderlying cause that is the faulty valves. Permanent treatments includesurgical excision of the diseased segments, ambulatory phlebectomy, andocclusion of the vein through thermal means.

Surgical excision requires general anesthesia and a long recoveryperiod. Even with its high clinical success rate, surgical excision israpidly becoming an outmoded technique due to the high costs oftreatment and complication risks from surgery. Ambulatory phlebectomyinvolves avulsion of the varicose vein segment using multiple stabincisions through the skin. The procedure is done on an outpatientbasis, but is still relatively expensive due to the length of timerequired to perform the procedure.

Minimally invasive thermal treatments for venous insufficiency eliminatethe need for general anesthesia and have relatively short recoverytimes. Endovascular thermal energy therapy is a relatively new treatmenttechnique for venous reflux diseases. With this technique, thermalenergy in the form of laser or radio frequency (RF) energy is deliveredby an energy delivery device that is percutaneously inserted into thediseased vein prior to energy delivery. In a laser therapy, an opticalfiber is used as the energy delivery device whereas in an RF therapy, RFelectrodes are used as the energy delivery device. The procedure for thethermal energy therapy involves inserting an introducer catheter orsheath and advancing it to within a few centimeters of thesapheno-femoral junction of the greater saphenous vein. In the case oflaser therapy, once the introducer catheter is properly positioned, aflexible optical fiber is inserted into the lumen of the catheter orsheath and advanced until the distal fiber tip is near the catheter tipbut still protected within the catheter lumen.

Once the energy delivery device is positioned within the vein, thetissue immediately surrounding the diseased vessel segment is subjectedto numerous needle punctures to make percutaneous injections of atumescent anesthetic agent. The injections, typically Lidocaine with orwithout epinephrine, are administered under ultrasonic guidance alongthe entire length of the greater saphenous vein into the perivenousspace. The tumescent injections perform several functions. First, theanesthetic injection inhibits pain caused from the application of energyto the vein. Second, the injection reduces the diameter of the vein tofacilitate efficient energy transmission to the vessel wall. Third, thetumescent injection also provides a barrier between the vessel and theadjacent tissue and nerve structures, which restricts the heat damage toonly the vessel itself and prevents non-target tissue damage. After theanesthetic injections are made through multiple puncture sites, theenergy delivery device is withdrawn as thermal energy is transferred tothe inner vein wall causing cell necrosis and eventual vein collapse.

For thermal treatment, the injection of tumescent anesthesia throughmultiple punctures along the diseased segment is considered a standardand necessary step in the treatment protocol. However, there are severaldisadvantages associated with such a conventional method ofadministering local anesthesia injections. The anesthetic injectionprocess is cumbersome and is the most time-consuming step in thetreatment procedure because of the number of punctures that has to bemade. Typically, injections are administered along the entire length ofthe greater saphenous vein in 2-3 cm increments. The total injectionlength varies but is usually between 30 and 40 cm.

Although these minimally invasive thermal treatments have been shown tobe effective and safe in eliminating the cause of varicosities, theyhave procedural shortcomings and complications that make them less thanideal. As discussed above, administration of tumescent anesthesia alongthe vein segment being treated requires careful administration andsignificant preparation time. In addition, reported thermal treatmentcomplications include pain for up to ten days following treatment,extensive bruising caused by vessel perforations, paresthesias, deepvein thrombosis and skin burns. The energy generator and disposabledevices necessary to perform the procedure are expensive and requirecapital investment by the practitioner. Another drawback of thermaltreatment of venous disease is the delivery device, which limitstreatment to veins of a diameter that will accommodate the device. Verytortuous veins cannot be treated by thermal ablation because thecatheter cannot successfully navigate the vein path.

Chemical occlusion, also known as sclerotherapy, is an in-officeprocedure involving the injection of an irritant chemical directly intothe vein. The drug is delivered either through direct injections with asmall gauge needle or more recently using a catheter placed in thetarget vein. The chemical acts upon the inner lining of the vein wallscausing them to occlude and block blood flow. The use of liquidsclerosing agents to treat varicosities has been utilized for decades,but has traditionally been limited to veins with diameters less than 5mm.

Sclerotherapy to treat larger diameter veins has not been widely useddue mainly to recommended volume limit of the drug and reported failurerates. Sufficient drug must be delivered to the treatment zone to fullydisplace the blood. A typical sclerosant, such as 3% sodium tetradecylsulfate, is volume limited to a maximum of 10cc per treatment, making itdifficult to treat larger veins. Catheter-directed sclerotherapy hasbeen attempted in larger veins such as the Great Saphenous Vein usingliquid sclerosant. Although initially successful, long-term failurerates are reportedly high, due to inadequate concentrations of drugbeing delivered to the vessel to cause durable closure and permanentdestruction of the vein. It is also postulated that blood flow in largerveins prevents the sclerosant from reaching the vessel wall insufficient concentration to effectively destroy the inner vessel walllining to occlude the vessel, resulting in a relatively low treatmentsuccess rate.

To minimize the dilution of the agent by blood, some practitioners haveutilized methods of emptying as much blood volume as possible from thevein being treated. Vein emptying may be performed by placing thepatient in a Trendelenberg position with the target leg higher than thetorso. Emptying may also be facilitated by the use of manual compressionusing either compression bandages or finger compression at the proximaland distal ends of the vein. These techniques, while lowering theoverall blood volume in the vessel, are time-consuming, requireadditional personnel to maintain compression during the procedure, areuncomfortable to the patient, and often result in incomplete bloodremoval and inconsistent treatment results.

Another sclerotherapy treatment that has recently emerged involves theuse of a foamed sclerosant to treat larger veins. A liquid sclerosingagent can be converted to a foam agent by forcing gas into the liquid,whereby creating microbubbles. Foam has several advantages over liquidsclerosant. Foamed sclerosing agents provide an increased concentrationof the sclerosing agent against the vessel wall. The theory is that thefoam displaces the blood in the vessel as the sclerosant is carried onthe exterior of the bubble. The foam contacts the vein wall deliveringhigh concentrations of the drug to the vein wall while minimizing theamount of drug introduced in to the patient. Theoretically, thesemicrobubbles contact and adhere more effectively to the vessel wall thanliquid because of their increased surface tension. Increasedconcentration of sclerosant allows the practitioner to use lesseramounts than with liquid sclerosant, whereby decreasing potentialcomplications associated with larger drug volumes. A further advantageof foam is that as it is injected, the foam displaces the blood locally,whereby minimizing the possibility of ineffective closure due todilution of the sclerosant by the blood. The displacement of bloodallows the practitioner to use less sclerosant.

When treating a vein with foam, some form of image guidance must be usedto insure foam reaches the intended location and does not enter the deepvenous system through the connecting perforating and tributary veins.The gas bubbles in the foam make it visible under ultrasound or acontrast agent may be mixed with the foam for visualization usingfluoroscopy.

While foam has been demonstrated to be more effective in vein closurecompared with infused liquid, it may cause significant neurological andsystemic complications if it travels to the arterial system. The gasbubbles that escape the superficial vessel and migrate to the deepvenous system are normally filtered out by the lung, but if the patienthas a patent foramen ovale (septal defect in the heart present inapproximately one-fourth the population), bubbles may pass from thevenous system into the arterial system, resulting in temporary visualproblems, reduced cognitive functioning and other more serious sideeffects such as stroke. The procedure must be closely monitored toprevent the expanding foam from entry into the deep venous systemthrough tributaries or perforating veins.

Some sclerotherapy delivery devices utilize one or more occlusionelements to isolate the treatment area, whereby minimizing dilution ofthe drug and reducing the total volume necessary for treatment. Once thedevice is properly positioned, the balloons or other occlusion elementsare inflated, creating an isolated vein segment to which the sclerosantis delivered. The balloons temporarily occlude blood flow through theisolated segment and also prevent the migration of drug into the deepvenous system. These devices, while effective in isolating the treatmentarea, are complicated devices which are expensive to manufacture andrequire additional training to use. In addition, complications can occurwhen the sclerosant is injected into the isolated segment. The pressurewithin the isolated segment, by the injection of sclerosant, may forcethe sclerosant into the deep venous system through perforator veins.This situation can lead to deep vein thrombosis, and in the case of foamsclerosant, may cause microbubbles to travel to the pulmonary system.

Therefore, it is desirable to provide an effective method of treatingvenous reflux utilizing a fluid sclerosant agent that targets the vesselwall without dilution. The method should avoid the associatedcomplications of foam migration to the deep venous system. The methodshould not require emptying the vessel of blood. The method should beable to treat large diameter veins without having to isolate veinsegments using complicated occlusion devices. It is cumbersome andtime-consuming to monitor the sclerosant as it is delivered to ensureinjected volumes are insufficient to migrate through the perforatorsinto the deep venous system. A method which eliminates or minimizesmonitoring and instead uses controlled volumes is desirable. Further, itis desirable to provide a method of vein closure that does not requirecomplicated and expensive equipment and delivery devices, and is simpleand fast for the practitioner. It would be advantageous for the methodto be performed using a catheter based system to avoid the time andcomplications associated with direct stick injections. Optimally, theuse of time-consuming tumescent anesthesia would be eliminated with thismethod. Finally, it would be advantageous to provide a method oftreatment that minimizes the total volume sclerosant required for theprocedure by directing concentrated drug directly at the vessel wall.

BRIEF DESCRIPTION

In brief, the presently preferred embodiment of the method of treating avascular disease includes insertion of a catheter into a patient's bodyvessel. The catheter has a lumen for receiving sclerosant fluid and aplurality of exits through which the sclerosant fluid is emitted underpressure as jets of fluid into the body lumen. The jets of fluid impingeon the wall of the body vessel and cover a treatment zone of the bodyvessel.

A moveable sheath over the catheter permits the uncovering of apredetermined portion of the exits, which portions can be up to 100percent, so as to permit the selection and targeting of a treatmentzone.

The jets of fluid preferably have sufficient force so as to impinge onthe wall of the vessel substantially orthogonal to the wall of thevessel to spread out over the vessel wall and to be minimally diluted bythe ambient blood.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a catheter/sheath assembly device with an occludingwire for use in the method according to the present invention.

FIGS. 2A and 2B are each an enlarged sectional view of the distal end ofthe device illustrating fluid flow path.

FIG. 2A illustrates the use of an occluding ball wire to close thedistal end hole of the catheter.

FIG. 2B illustrates the use of a standard guidewire to close the endhole.

FIG. 3A-3E is a series of plan views of the device within the veindepicting the method of the current invention.

FIG. 3A depicts a plan view of a vein segment to be treated with theguidewire in place.

FIG. 3B is a plan view of the vein segment to be treated with thecatheter/sheath assembly device with occluding ball wire within thevein.

FIG. 3C is a plan view of the vein segment to be treated with sheathpartially withdrawn to expose the set of pressure responsive outlets.

FIG. 3D is a plan view of the vein segment depicting the flow directionof the sclerosant through the catheter lumen and into the wall of thevein.

FIG. 3E is a plan view of the vein segment with the catheter/sheathassembly being withdrawn from the treated vein.

DESCRIPTION OF TEE PREFERRED EMBODIMENTS

A method of treating venous reflux utilizing a sclerosant agent will nowbe described. The method of sclerosing a vessel utilizes acatheter/sheath assembly device 1, illustrated in FIG. 1 and in FIGS. 2Aand 2B. FIG. 1 is a plan view of the assembled device shown with anoccluding ball wire 4. The sheath 2 is comprised of a sheath hub 5, adistal tip section 6, a lumen extending from the sheath hub 5 to thedistal tip 6 and terminating in a sheath end hole 18. The sheath hub 5may include a seal to prevent blood and sclerosant from leaking. Thesheath 2 body may be reinforced with ultrasonically visible materialsuch as braided or helically wound medical grade stainless steel wire.The reinforced shaft provides the user with enhanced flexibility andpushability in addition to improved visibility under ultrasound.

The catheter component 3 is coaxially arranged within the sheath lumenand is comprised of a catheter hub 8, a distal tip 9, and a lumen 10extending from catheter hub 8 to the distal tip 9 and terminating incatheter end hole 19. Extending along a portion of the catheter arepressure responsive exits or outlets 11 which form an infusion zone 20,shown in FIGS. 2A and 2B. The maximum length of the infusion zone 20 isidentified by radiopaque markers 14 located at the distal and proximalend of the infusion zone. As shown in FIG. 1, connected to the catheterhub 8 is a standard Y-hub connector 24 to provide a port for injectingthe fluid sclerosant. A compression gasket 26, such as a touhy-borstgasket is tightened around the guidewire to prevent drug leakageproximally.

The distal tip of the catheter 3 and sheath 2 may be designed to enhancevisibility under fluoroscopy and/or ultrasound. The distal tip portionof catheter or sheath may be loaded with tungsten or other radiopaquefiller to increase the density whereby providing enhanced radiographicvisibility. Additionally, the distal tip of either component may bedesigned for enhanced visibility under ultrasound by incorporatingstructure to increase echogenicity. The tip of the sheath is visibleunder fluoroscopy and ultrasound so that, in conjunction with the distalmarking on the catheter, the length of the infusion zone can be adjustedto match the treatment zone. Examples of such structures that willincrease ultrasonic reflection include incorporating microspherescontaining a gas into the tip, a band of braiding or other metallicmaterial embedded within the tip and a tip containing an enclosed airspace. As will be discussed in more detail below, the occluding ball ofthe occluding wire embodiment may also be designed for enhancedvisibility. Other methods of incorporating imaging visibility elementswithin the catheter and/or sheath are known within the art and areincorporated herein.

FIG. 2A illustrates a method in accordance with the device and techniquedescribed in U.S. Pat. No. 5,250,034 and U.S. Pat. No. 6,283,950. Anoccluding ball wire 4 is comprised of a wire 34, a distal hole occludingball 32, and a floppy distal end segment 36 which extends distallybeyond the catheter end hole 19. The occluding ball 32 seats within theinternal distal taper of the catheter, sealing and preventing fluid flowthrough the end hole. The occluding ball 32 may be formed ofechogenically visible material to enhance visibility of the catheterdistal tip under ultrasound guidance.

The Y-connector hub 24 shown in FIG. 1 is connected to catheter hub 8and is used to facilitate the delivery of sclerosant through the sidearm 25. Alternatively, the Y-connector hub 24 may not be necessary ifthe occluding wire terminates within the body of the hub, as describedin U.S. Pat. No. 6,283,950. The hub may include a through lumen for theintroduction of sclerosant fluid into the catheter lumen. In thisoccluding ball embodiment, the physician injects the sclerosant directlythrough occluding wire hub.

FIG. 2B illustrates use of a standard guidewire 30 for occlusion of thecatheter end hole 19. As shown in FIG. 2B, the catheter end hole 19 isdimensioned to fit snuggly against the outer diameter of the guidewire30, effectively occluding end hole 19 and creating an annular fluidchannel 10 between the guidewire 30 and inner wall 12 of the catheter.As an example, a 5 French catheter has a 0.067 inch outer diameter and a0.048 inch inner diameter. The catheter lumen tapers down distally to anend hole 19 having an inner diameter of approximately 0.036 inch toensure occlusion by standard 0.035 inch guidewire. A 5 French sheathwould have dimensions of 0.085 inch outer and 0.068 inch innerdiameters. The sheath tip 6 would be sized to seal upon the catheterouter wall. Other dimensions are within the scope of this invention.

The length of the catheter is dependent on the vein being treated. Ifthe origin of reflux is associated with the Great Saphenous Vein forexample, the vein segment being treated would typically range from 30-40cm. A vein segment of this length would need a catheter with an infusionzone 20 of approximately 40 cm to ensure complete drug coverage of thevein wall. During operation, the sheath 2 is retracted relative to thecatheter 3 to uncover the desired length of the infusion zone 20. Acatheter measuring approximately 80 cm in length would allow the sheathto be retracted the 40 cm needed to fully expose the entire infusionzone. Shorter catheters with shorter length infusion zones could be usedto treat smaller length segments.

The infusion zone 20 is comprised of a pattern of pressure responsiveoutlets 11 which, by example, are each approximately 0.015 to 0.30 inchin length. A typical outlet pattern includes sets of four outletslocated every 900 radially along the distal shaft of the catheter 3. Theoutlets 11 are approximately 5 mm apart in rows that are parallel toeach other. Other outlet 11 dimensions and infusion zone patterns arewithin the scope of this invention.

As will be described in greater detail later, a syringe containing thesclerosant fluid is used to inject the fluid through the port 25 of theY-hub connector 24. The fluid flows through annular channel 10 exitingthrough those pressure responsive outlets 11 that are not covered by thesheath.

The sheath also functions to protect the insertion site track from theunintentional delivery of sclerosant into the adjacent tissue. Injectionof sclerosant into tissue is known to cause tissue necrosis, which maylead to skin ulceration and other complications. If the user misalignsthe catheter so that one or more outlets are within the insertion trackyet outside of the vein, subsequent injection of sclerosant will flowthrough the outlets and penetrate the tissue immediately surrounding theinsertion track. Because the distal end of the sheath is readilyvisible, placing the catheter through a sheath prevents this potentialcomplication by ensuring that all outlets outside of the vein arecovered by the sheath wall thus preventing sclerosant from beingdelivered externally to the vein. An introducer sheath can be employedto perform this protective function.

The method of using device 1 will now be described with reference toFIG. 3A-3E. The treatment procedure begins with the standardpre-operative preparation of the patient as is well known in thetreatment art. The patient is examined with ultrasound to identify andlocate the source of venous reflux, typically the Great Saphenous Vein.Treatment is not necessarily limited to the Great Saphenous Vein;diseased segments of the small saphenous vein and other veins may betreated using the improved method described herein. The sapheno-femoraljunction and any anatomical variations of the venous system are alsoidentified during pre-treatment ultrasound. After the ultrasoundexamination, the patient's leg is draped and cleansed in preparation forthe procedure.

With prior art thermal treatment methods, the patient's diseased venoussegments are marked on the skin surface. Typically, ultrasound guidanceis used to map the greater saphenous vein from the sapheno-femoraljunction to the popliteal area. The physician marks the route of thevein with a marker under ultrasound guidance. The purpose of thismapping is to provide a visual identifying line for the physician tofollow when injecting perivenous tumescent anesthesia along the lengthof the diseased vein. As persons of ordinary skill in the art canappreciate, mapping of the vein is a very time-consuming step for thephysician. The present invention advantageously minimizes the time spentmapping the vein since tumescent anesthesia is not required with themethod of the current invention.

Administration of tumescent anesthesia typically involves making 10 to20 needle punctures to deliver 10 to 20 perivenous injections underultrasound guidance. The injections are time-consuming, can be painfulto the patient, leave multiple puncture wounds and may increase bruisingand post-procedure complications. According to the principles of thepresent invention, however, the delivery of tumescent anesthesia iseliminated. Instead, only a small injection of local anesthesia isnecessary at the entry site.

After the patient has been prepped, the Great Saphenous Vein is accessedusing a standard Seldinger technique. A small gauge needle is insertedthrough the skin and into the vein lumen. A guide wire 30 is insertedthrough the needle and advanced to the sapheno-femoral junction. Theentry needle is removed, leaving the guidewire 30 in place within thevein 16, as shown in FIG. 3A. The sheath/catheter assembly 1 is thenadvanced over the guidewire 30 into the vein and tracked over the wireuntil the assembly distal end is located just proximal of thesapheno-femoral junction. Advancement of the device 1 through tortuousvein segments is facilitated by the flexible material of the devicewhich tracks through the curvature of the vessel lumen without kinking.Navigating through tortuous vessel segment is more difficult with priorart thermal treatment devices such as an RF electrode catheter or laserfiber, which are stiff and do not track as easily.

Once the catheter/sheath assembly is properly positioned within thetarget vein 16, the guidewire 30 is removed. The occluding ball wire 4is then inserted through the catheter and advanced until the occludingball 32 seats against the inner taper of the catheter distal tip,effectively sealing the distal end hole 19, as shown in FIG. 3B. If astandard guidewire is being used rather than an occluding ball wire, theguidewire 30 remains in place within the lumen 10 of the catheter 3during the procedure, such that the guidewire effectively occludes theend hole 19, as previously illustrated in FIG. 2B.

The placement of the catheter/sheath assembly within the vessel willnormally induce a significant and prolonged vein spasm. This spasm isdesired and beneficial in that it will reduce the inner diameter of thevein being treated, which will cause a corresponding reduction in volumeand flow of the blood in the vein. The reduction in blood volume of thetarget vein limits the extent of dilution of the sclerosant whileincreasing the amount of drug that will reach the vessel wall. If thetargeted vein does not spasm, a vaso-constricting drug such asepinephrine may be injected intravenously through the catheter to inducevessel spasm.

With the distal end hole 19 of the catheter 3 occluded by either theoccluding ball 32 or a guidewire 30, the sclerosant is directed throughthe pressure responsive exits 11 in the catheter wall. This design thusdecreases the probability that the sclerosant will migrate to the deepvenous system by preventing a forward flowing jet of sclerosant from thedistal end hole of the catheter. Advantageously, the sclerosant isprevented from traveling into the central system without the use of anocclusion balloon, manual compression or other adjunct occlusion devicesor techniques.

Once the catheter/sheath assembly 1 is properly positioned within thetargeted vein 16, the sheath 2 is retracted while holding the catheter 3stationary to expose the desired length of pressure responsive outlet 11pattern. FIG. 3C illustrates exposure of all outlets 11 in the infusionpattern. The user may adjust the infusion pattern length by withdrawingthe sheath 2 to selectively adjust the desired length of the infusionpattern. The sheath 2 will prevent fluid flow through the coveredoutlets 11 because the fluid follows the path of least resistance andwill exit from the non-covered outlets rather than the covered outlets.Radiopaque or ultrasonically visible markers 14 may be provided on thecatheter 3 to identify the distal and proximal ends of the maximuminfusion outlet zone and on the distal tip 6 section of the sheath 2 toallow the user to discern the location of the sheath 2 relative to theoutlet 11 pattern.

Alternatively, the physician may pre-set the exposed infusion zonelength prior to inserting the device into the vein. The catheter mayoptionally contain markings along the shaft to assist in identifying thelength of the exposed infusion zone. The sheath hub 5 is aligned with amarking on the catheter that indicates the exposed infusion length. Asan example, if a 10 cm infusion zone is desired, the physician alignsthe sheath hub to the 10 cm marking on the catheter. A compressiongasket may be attached to the sheath hub to ensure that thecatheter/sheath alignment remains stationary during insertion andadvancement through the target vein.

Sclerosant is delivered under pressure using a standard syringe attachedto a Y-hub connector of the catheter 3. Other delivery means may be usedsuch as a pressurized reservoir of sclerosant. As used herein, asclerosant refers to any fluid that acts upon the inner vessel wallcausing a diameter reduction and subsequent vessel wall destruction andocclusion. Sclerosants may include solutions of hypertonic saline,polidocanol, sodium tetradecyl sulfate, chromated gylcerin, iodine andhypertonic glucose. Sclerosant fluid as defined herein may be liquid orfoam in varying concentrations. The sclerosant may also be combined withother adjunctive drugs such as vaso-spasming fluid, anesthetics, salineor other fluids. Examples of adjunctive drugs include but are notlimited to ephrephrine, Lidocaine and Marcaine. Other sclerosants andadjunctive drugs also fall within the scope of this invention.

The drug may be infused into the catheter 3 in a single bolus ormultiple injections of small boluses. It is estimated that a smallvolume of drug, typically 0.2cc per bolus, can effectively cover a veinsegment of approximately 20 cm in length. Under forceful injections, thefluid advances into the annular fluid passageway 10 formed between theoccluding ball wire 4 and the catheter 3 sidewall. Occlusion of thecatheter 3 end hole 19 by occluding ball 32 causes the drug to exit fromthe exposed outlets 11 in the side wall of the catheter 3 into the vein16.

As described in U.S. Pat. No. 5,250,034, incorporated herein byreference, the outlets 11 are of the same geometry and material and thusthe pressure which will open each outlet 11 is the same. When fluid isinfused into the catheter lumen 10, the pressure rise within thecatheter lumen 10 will be a uniform pressure on all outlets 11. Alloutlets 11 will open simultaneously at a predetermined internal pressureto allow the drug flow to exit from the catheter lumen 10 in a uniformmanner along the entire length of the infusion pattern, as shown in FIG.3D.

The design and uniform spacing of the pressure responsive outlets 11ensures uniform and rapid delivery of the sclerosant fluid along theentire vein segment being treated. As illustrated in FIG. 3D, thepressure responsive outlets 11 direct the fluid jet 17 of the drug at asufficient force to pass through the remaining blood to reach the veinwall without being materially diluted. Once it reaches the vessel wall,the sclerosant will disperse covering a larger area of the vein wall.

The laminar flow of blood through the vein means that the velocity offlow varies from a maximum at the center of the vessel to a zerovelocity at the vein wall. Once the sclerosant reaches the vessel wall,the near zero velocity of the blood flow is insufficient to dilute andwash away the drug from the walls. Thus, the design of this inventionmaximizes the vessel wall/drug contact by directing a high velocity drugcolumn at a high angle (preferably close to 90 degrees) to the vesselwall. The high velocity drug column is directed through the highervelocity blood flow toward the vessel wall where the blood flow isminimal and will not cause dilution of the drug. Applicants believe thatthe effectiveness of method is enhanced as the column of sclerosantapproaches a 90 degree angle relative to the wall of the vessel. Inreaction to contact with the sclerosant, the vein wall will furtherspasm as shown in FIGS. 3D and 3E, whereby further reducing the diameterof the vein.

The physician will deliver single or multiple boluses of drug to thevein to achieve closure, depending on the length of the vein segmentbeing treated. The recommended amount of sclerosant required to achievepermanent closure of the vein is based on inner vein wall surface area.Sufficient sclerosant must be infused to completely cover the vesselwall. Longer vein segments will require more sclerosant.

The method of the current invention is advantageous in that the drug isbeing delivered directly to the inner vein wall, with minimal or nodilution by the blood. The force of the fluid jet and its directed focusat the vessel wall provide improved drug/wall coverage over prior artmethods. The volume of fluid per jet is small but the velocity is high,providing a force capable of penetrating through the blood to contactthe vessel wall. Significantly less drug volume is required to achievethe desired impact than volumes required for an end hole catheter ordirect injections which are directed into the blood stream where thedrug is diluted by the blood flow. The method is also advantageous oversclerotherapy devices that utilize porous material through which thedrug is dispersed at lower velocity into the vein, resulting in lesssclerosant reaching the vein wall.

If additional sclerosant infusions are desired to ensure complete wallcoverage, the injection procedure described above is repeated.Alternatively, the method of this invention may include sequentiallydelivering sclerosant to segments of the vein. With this method, ashorter catheter or a catheter with a shorter infusion length may beutilized. The sclerosant is first delivered through the catheter to thedistal most segment of the vein. After delivering a first bolus ofsclerosant, the catheter is repositioned proximally at the next segmentto be treated and another injection is delivered to a new section ofvein. This process is repeated until the entire length of the vein hasbeen treated. A shorter length catheter device is easier to maneuver andcontrol than a longer length catheter. In addition, a single device canbe used to treat various lengths of vein. Thus, this method results inreduction of inventory that must be maintained by the medical facility.

When an effective dose of sclerosant has been delivered to the veinbeing treated to achieve closure, the catheter/sheath assembly 1 isremoved along with the occluding ball wire 4, as illustrated in FIG. 3E.The access site is then closed using method well known the art. Thetreated leg is then wrapped in compression dressing and covered with acompression stocking to prevent any blood flow through the occludedvein.

Thus, the method disclosed herein provides an effective means oftreating varicosities with advantages over prior art treatment methods.The design and operation of the pressure responsive outlets 11 providesan effective means of optimizing vessel wall/drug contact without manualemptying or isolation of the vein segment prior to the procedure. Theuse of tumescent anesthesia associated with thermal treatments such asRP or endovenous laser closure is eliminated using the method of thisinvention. Common complications of thermal treatments including vesselperforations, bruising, deep vein thrombosis and skin burns are avoided.The design of the catheter/sheath assembly allows the physician to treatvery tortuous vein segments, due to the flexibility and trackability ofthe catheter. Using a simple catheter/sheath device, a small volume ofliquid drug can be optimally administered directly to the vessel wall toachieve effective closure of a vessel. The procedure and method of thisinvention is easy, uses an inexpensive, uncomplicated device and isfast, safe and effective.

Although the particular embodiments of the method of the presentinvention have been described in detail, it will be understood thatvarious omissions, modifications, substitutions and changes in the formsand details of the device illustrated and in its operation can be madeby those skilled in the art without departing in any way from the spiritof the present invention. Any feature may be combined with another inaccordance with the invention and are attended to fall within the scopeof the appended claims.

For example, the sheath component may be omitted. Instead, a catheter isinserted over a guidewire and sclerosant is injected through the annularchannel as described above. Although the infusion zone length cannot bevaried with this embodiment, the elimination of the sheath componentprovides the user with a less expensive device that is simpler to use.Optionally, catheters with different length infusion zones can be usedto accommodate different treatment segment lengths.

As another example, a plurality of small exit holes located in theinfusion zone of the catheter shaft may be used to deliver the drug. Theexit holes are each of a diameter sufficiently small to providesubstantially the same velocity and volume of sclerosant through eachexit in a uniform manner along the entire length of the infusionpattern. As an example, circular exits with a diameter of 0.0025″ to0.005″ deployed circumferentially and longitudinally along thepre-determined infusion zone will produce a jet of sclerosant at asufficient force to pass through the remaining blood to reach the veinwall without being materially diluted. The exits may be formed usinglaser-cutting processes well known in the art.

It is also contemplated that foam sclerosant compositions may providesufficient flowability characteristics to be usable as a fluid in themethod of this invention. Although foams are compressible and willtherefore create a lower velocity jet impinging on the vessel wall, foamcharacteristics including bubble size and air to liquid ratios may bemodified to optimize delivery through the device and method describedherein whereby achieving the treatment goals of vein wall destructionand subsequent closure. By directing the foam sclerosant through theoutlets on the side wall of the catheter at a substantially right anglerelative to the vessel wall, smaller volumes of the foam sclerosant maybe used with significantly less migration than would occur with an endhole catheter or injection needle. By controlling the migration of foaminto the deep venous system, neurological and other treatmentcomplications associated with gas-based sclerosants are minimized.Additionally, directing foam sclerosant through the outlets on thesidewall of the catheter allows the user to specifically target thetreatment zone of the vessel.

What is claimed is:
 1. A method of treating a vascular disease comprising: inserting into a body vessel a catheter having a lumen, an end hole and a plurality of exits longitudinally disposed along the sidewall of the catheter, the end hole having a proximal opening and a distal opening; inserting through the catheter an occluding wire having an occluding element having a larger size than the size of the end hole so as to occlude the proximal opening of the end hole; and delivering a sclerosant fluid into the lumen under pressure such that the fluid flows through the exits and impinge on the wall of the body vessel without using an occlusion balloon and without using tumescent anesthesia.
 2. The method of claim 1 wherein the exits are disposed circumferentially along the sidewall.
 3. The method of claim 2, where the step of delivering includes delivering the fluid along the entire circumference of a predetermined treatment zone of the body vessel.
 4. The method of claim 1, wherein the step of delivering a sclerosant fluid into the lumen under pressure further includes jets of the fluid flowing through the exits.
 5. The method of claim 4, wherein the fluid is impinging on the wall of the vessel substantially orthogonal to the wall.
 6. The method of claim 1 wherein the step of delivering includes selecting exits to define an infusion zone which substantially matches a predetermined body vessel treatment zone.
 7. The method of claim 1 wherein exits comprise of pressure responsive slits.
 8. A method of treating a varicose veins comprising: inserting into a varicose vein an infusion catheter having a lumen, an end hole and a plurality of exits longitudinally disposed along the sidewall of the catheter, the end hole having a proximal opening and a distal opening; inserting through the catheter an occluding wire having an occluding element having a larger size than the size of the end hole so as to occlude the proximal opening of the end hole; inducing vessel spasm without the use of tumescent anesthesia; and delivering a sclerosant fluid into the lumen under pressure such that the fluid flows through the exits without using an occlusion balloon.
 9. The method of claim 8, wherein the exits are pressure responsive slits.
 10. The method of claim 8, wherein the sclerosant fluid is delivered at a substantially uniform velocity.
 11. An apparatus for treating a vascular disease comprising: a catheter having a lumen, an end hole and a plurality of exits longitudinally disposed along the sidewall of the catheter, the end hole having a proximal opening and a distal opening, an occluding wire adapted to be inserted through the catheter, the occluding wire having an occluding element having a larger size than the size of the end hole so as to occlude the proximal opening of the end hole, a delivery device comprised of at least the catheter and the occluding wire that delivers a sclerosant fluid into the lumen under pressure to pass through the exits which impinge on the wall of a blood vessel in which the catheter is deployed without using an occlusion balloon and without the use of tumescent anesthesia.
 12. The apparatus of claim 11, wherein the exits are pressure responsive slits.
 13. The apparatus of claim 12, wherein the slits are longitudinally and circumferentially placed along the sidewall of the catheter.
 14. The apparatus of claim 13, wherein the slits are normally in a closed position restricting fluid communication between the lumen and the blood vessel.
 15. The apparatus of claim 15, wherein the slits open fluid communication between the lumen and the blood vessel once the sclerosant fluid is delivered at a pressure sufficient to open the slits.
 16. The apparatus of claim 11 further comprising: a sheath positioned over a portion of the catheter to prevent delivery of the sclerosant from any of the exits covered by the sheath.
 17. The apparatus of claim 16, wherein the sheath is moveable.
 18. The apparatus of claim 11, wherein the exits are configured to provide fluid jets at a substantially uniform velocity.
 19. The apparatus of claim 18, wherein the fluid jets prevent dilution of the sclerosant fluid being delivered.
 20. The apparatus of claim 19, wherein the sclerosant fluid being delivered is sufficient to occlude the blood vessel. 